Technical Abstract:
Ceratoides lanata var. lanata (common winterfat) is a prolific chenopod on western rangelands throughout the western United States. The plant is valued by livestock producers for its nutrient content and palatability to livestock. On the Jornada Experimental Range, records collected at various times throughout the twentieth century all indicate that C. lanata is unpalatable. The availability of palatable and unpalatable phenotypes makes C. lanata a useful model for the identification of secondary compounds influencing diet selection. In this study, actively growing shoots from local winterfat and Hatch winterfat from Snow Field Station in Utah were sampled in an early growth phonological stage. Nonvolatiles were extracted in 80% ethanol and separated by liquid chromatography with photodiode array detection. Several peaks show significantly different concentrations between populations. Additional populations are currently being sampled at early, mid, and late growth stages and will be analyzed a well. We are working to locate and identify additional unpalatable populations throughout the southwest. Peaks which are consistently and significantly different between palatable and unpalatable populations will be isolated and identified by LCMS in order to determine the influence these chemicals have on diet selection among large ruminants.